Air extractor pump for waterbeds

ABSTRACT

The invention relates to an air extractor pump for waterbeds comprising a piston ( 1 ) held with longitudinal slideability in a cylinder ( 4 ), wherein the piston ( 1 ) and the cylinder ( 4 ) each are equipped at their back ends as seen in insertion direction ( 3′ ) with a valve flap ( 9, 17 ) closeably covering a through-bore ( 33 ) each, wherein the front end of the piston ( 1 ) as seen in insertion direction ( 3 ′) is equipped with a discharge bore ( 5 ), and wherein at the back end of the cylinder ( 4 ) as seen in insertion direction ( 3′ ), a thread ( 32 ) is provided wherewith it can be screwed onto a correlated screw neck ( 12 ) of a filler neck ( 10 ) of a waterbed, wherein the valve flaps ( 9, 17 ) are attached in the area of separately constructed valve cases ( 15, 16 ), wherein the piston-side valve case ( 16 ), as well as the cylinder-side valve case ( 15 ) are each equipped with a plug-in piece ( 19, 24 ) engaging with the plug-in receptacles ( 29, 30 ) of the piston ( 1 ) or the cylinder ( 4 ), respectively, in a correlated, sealed snap-in connection. The object is to create an air extractor pump functioning with operational reliability, which can be assembled free from adhesive and manufactured at lower cost and with greater functional reliability.

This application claims priority to German Patent Application No. 102007060957.6 filed on December 14, 2007 incorporated herein in its entirety.

The invention relates to an air extractor pump for waterbeds according to the preamble of patent claim 1.

An air extractor pump of this type comprises a piston constructed in a tube-shaped cylinder, said piston being able to slide longitudinally therein and carrying at the front end bottom side, a valve flap closeably covering a through-bore, while the opposite end of said piston is equipped with a discharge bore.

The piston can be manually slid longitudinally within a cylinder constructed as case open at the top, and the cylinder also has at its bottom-side end a valve flap closing a correlated through-bore, while simultaneously, at the lower end of the cylinder, a screw-on adapter is provided permitting the lower end of the cylinder housing to be screwed onto a correlated filler neck of a waterbed.

In order then to remove any air bubbles trapped in a waterbed, the method is known of lifting the filler neck of the waterbed in order to raise the same above the level of the water in the waterbed. Subsequently, the filler neck which is firmly connected to the waterbed is screwed in at the underside of the cylinder in a corresponding screwing motion and connected tightly to the cylinder.

The piston rod then is moved up and down, and the pump used generally is very simple to operate. This means that when the piston is pulled out of the cylinder housing, air is sucked out of the filler neck of the waterbed and thereby reaches the intermediate space between cylinder and underside of the piston. With the next piston stroke, now in reverse direction, the air stored in the said intermediate space is moved through the piston, because the cylinder-side valve flap is closed in this process and the piston-side valve flap is opened. Thereby, the air is displaced to the cylinder and discharged through the piston upwards and outside.

In principle, an air extractor pump of this type has proven itself; however, the manufacturing cost of a pump of this type is extraordinarily high and it does not function with sufficient operational reliability.

It has been determined that in air extractor pumps known to the art the screw-on adapter disposed at the underside of the cylinder is only glued to the case-shaped cylinder housing, which is associated with the disadvantage that during the gluing process, adhesive residue can penetrate into the interior of the cylinder, thereby impairing the stroke motion between piston and cylinder. Furthermore, adhesive residue leaked to the outside impairs the appearance and is difficult to remove from the external surface of the piston. Moreover, the adhesion is not ensured to be firm and tight all around, which is associated with the disadvantage that unwanted air can penetrate between the screw-on adapter at the underside of the cylinder and the cylinder itself during the pumping process.

Moreover, a method is known to the art whereby the valve flap—comprising an elastomeric bendable strap—is attached immediately to the cylinder-side screw-on adapter, which is associated with a high amount of labor. Valve flaps of this type are attached only with a pin inserted through a corresponding bore in the bottom of the screw-on adapter, and the pin is subsequently fused. This type of attachment does not ensure secure attachment of the valve flap, and in addition, the problem arises that during the fusing process, fusing material may penetrate through the said bore to the upper side of the valve flap, thereby preventing the same from forming a tighter closure on the bottom of the screw-on adapter.

Furthermore there again, penetrating adhesive residue possibly reaching the said sealing surface when the screw-on adapter is being glued to the cylinder housing, may lead to a malfunction of the pump.

A further disadvantage lies in the fact that the through-holes for the sealing coverage by the valve flaps are only bored, and as a rule, are also not deburred. Due to the resulting burs, a secure sealing surface in direction of the elastomeric bendable valve flap is not achieved.

A further disadvantage lies in the fact that for the piston, as well, the only method known to attach the valve flap disposed at the underside of the piston, on the inside, is through the entire length of the piston with a corresponding special tool. Consequently the disadvantage arises that a secure attachment of the valve flap in the piston cannot be ensured and that the sealing surface to be found by the valve flap at the bottom of the piston is not subjected to clean finishing work.

Therefore then, as a whole, an air extractor pump according to the prior art has the disadvantage that the parts mentioned are only glued on and that the attachment of the valve flaps is insufficient and not well sealed.

The invention thus has the object of refining an air extractor pump for waterbeds of the type mentioned above in such a way that the same will function with operational reliability, can be assembled free from adhesive, and can be manufactured at lower cost and with higher functional reliability.

In order to achieve the object of the invention, the invention is characterized by the enabling disclosure of claim 1.

An essential feature of the invention lies in the fact that the valve flaps are attached in the area of separately constructed valve cases, wherein the piston-side valve case, as well as the cylinder-side valve case each have a plug-in piece and engage with the piston as well as with the cylinder in a correlated, sealed plug-in connection.

Based on the enabling disclosure, the essential advantage arises that an adhesive-free function with absolute operational reliability of the air extractor pump is ensured by the fact that the piston-side valve case as well as the cylinder-side valve case are each equipped with an external plug-in piece to plug the same into the piston or the cylinder, respectively. Thus, instead of an assembly with adhesives, a plug-in assembly is proposed, and furthermore it is proposed that the valve flaps themselves no longer be connected immediately and firmly with surfaces connected to the cylinder and the piston, but that rather they be attached in separate parts. The said separate parts, which according to the invention are constructed as valve cases, have the advantage that they can be finished very well, since the through-hole located therein is produced free from burs, because it is produced in an injection molding procedure, and that therefore, a bore with subsequent deburring is not needed.

In the same way, therefore, the advantage arises that the respective bottom sides of the valve cases containing the through-holes are constructed absolutely evenly and cleanly and without any contamination, since these have also been produced in the said injection molding procedure and need no further finishing work.

Thanks to the plug-in assembly of the two valve cases into the cylinder or the piston, the advantage arises that there is no longer the danger that leaking adhesive residue stain the sealing surface for the valve flap in the valve case, thereby making the function of the entire air extractor pump questionable.

A further feature of the invention lies in the fact that the respective valve flap can be snapped into a correlated slit in the bottom surface of the respective valve case in the manner of a snap-in connection. Thereby, a particularly simple attachment with particular operational reliability is achieved, since the said snap-in connection absolutely prevents a later separation of the valve flap, because the snap-in connection works with operational reliability, and furthermore, the secure seating of the valve flap can be easily checked by the person assembling the air extractor pump. This was not possible with the prior art, because there, the valve flaps had to be disposed immediately in deep components of the piston and the cylinder and had to be attached with the aid of very long construction tools. This is avoided according to the invention.

Thanks to the fact that an adhesive connection is avoided overall, a preferred refinement of the invention provides that the cylinder-side valve case is held in the cylinder in a way to be prevented from twisting, in order to ensure that the pushed-on valve case is not unintentionally twisted when it is screwed onto a correlated external thread of the filler neck of a waterbed.

An antitwist protection of this type is also simply achieved by the fact that with the injection molding tool for the manufacture of the cylinder case, radially inward-pointing ridges are constructed to work in conjunction with correlated longitudinal grooves on the external circumference of the valve case, fixing the same without the possibility of twisting.

The subject of the present invention does not only derive from the subject of the individual patent claims, but also from the combination of the individual patent claims with one another.

All data and features disclosed in the documentation, including the abstract, and in particular, the spatial structure represented in the drawings are claimed as essential for the invention in so far as they are novel individually or in combination in relation to the prior art.

Below, the invention is explained in more detail with reference to drawings representing only one embodiment. Further features and advantages essential for the invention ensue from the drawings and the description thereof.

The drawings show in:

FIG. 1: the lateral view of a filler neck connected to a waterbed and the closure organs thereof;

FIG. 2: the representation of a stroke of the air extractor pump during withdrawal of the piston from the cylinder;

FIG. 3: the same image as in FIG. 2 during push-back of the piston into the cylinder;

FIG. 4: the complete representation of the air extractor pump;

FIG. 5: highly shortened perspective representation, partially cut open, of the air extractor pump;

FIG. 6: explosion-like extended representation, as compared to FIG. 5, partially in a sectional view;

FIG. 7: schematic sectional view of the piston with the components thereof;

FIG. 8: schematic sectional view of the cylinder and the filler neck to be connected thereto.

In FIG. 1, it can be seen that a waterbed is connected to a filler neck 10, wherein the water 11 is reaching a particular level, and wherein air 42 has accumulated in an intermediate space.

In the normal case, the filler neck 10 is equipped with an upper screw neck 12, and in closed state, the filler neck 10 is secured by an internal closure cap 13 and the latter, on its part, by an external screw-on cap 14.

In order now to remove the air 42 from the opened filler neck 10, the air extractor pump 20 according to the invention is placed on the filler neck 10, and the underside is connected to the screw neck 12 of the filler neck 10 by means of a screwed connection, as shown in FIG. 2.

Insofar as the piston 1 is pulled out of the cylinder 4 in direction of the arrow 3, the valve flap 9 opens in the cylinder 4 at the lower valve case 15, whereby the said valve flap 9 assumes its position 9′, and air is sucked out of the filler neck 10 in the direction of the arrow 8 into the interior of the cylinder 4.

At first, it remains in the position of FIG. 2 in the interior of the cylinder 4.

When now, by manual pressure on the head 2 the piston 1 is moved downwards in the direction of the arrow 3′, the bottom-side end of the piston 1 penetrates into the interior of the cylinder 4, causing displacement, and the valve flap 9′ assumes its closed position 9 while simultaneously, in the valve case 16 disposed in the piston 1, the valve flap 17 disposed therein opens to assume the position 17′, and the air there escapes upwards in the direction of the arrow 6.

With further displacement of the piston 1 into the cylinder 4, the air then finally flows out in the direction of the arrow 7 through an upper bore 5 disposed in the head 2 of the piston 1.

After suitable extraction of air with several extracting strokes then the entire filler neck 10 can be manually lifted upwards, as is shown in FIG. 3, and in this lifted position, the filler neck is again closed with the closure cap 13 and the screw-on cap 14.

The air volume 42′ according to FIG. 2 consequently was reduced to the air volume 42 according to FIG. 1.

FIGS. 5 and 6 show further details of the invention. It can be seen that the cylinder-side valve case 15, as well as the piston-side valve case 16 are each plugged into correlated plug-in receptacles 29, 30 as plug-in connections. The piston-side valve case 16 thus has the plug-in receptacle 29, while the cylinder-side valve case 15 has the plug-in receptacle 30 in the cylinder 4.

It is of importance that each valve case 15, 16 contains a bottom 18 forming the sealing surface for the valve flap 9, 17 attachable to the said bottom.

In this process, the radially exterior screw neck 12 is screwed into a correlated internal thread 32 on the cylinder-side valve case 15, where in addition, a circular collar 25, in axially downward-extended construction, supports the possibly folding screw neck 12 of the filler neck 10 and protects the same against folding over.

This is shown in FIG. 5, where it can be seen that the circular collar 25 has a particular axial length so that it covers several thread turns of the screw neck 12 of the filler neck 10 so that it can be screwed in without folding over and with relatively light manual force, and here then the upper protuberance 39 on the screw neck 12 rests sealingly against the bottom of the circular groove 26 in the area of the cylinder-side valve case 15, as shown in FIGS. 5 and 8.

The ridges 31 disposed radially inward in the interior of the cylinder 4 and recognizable in FIG. 6 form a twist protection 27 in connection with the valve case 15.

Here, the valve case 15 is equipped with a radially exterior, circumferential plug-in piece 24 comprising several circular bulges 41 disposed in parallel and circumferentially. The said plug-in piece 24 serves to plug the valve case 15 sealingly into the interior of the cylinder 4, where it is held sealed and twist-protected with the twist protection devices 27.

The same is true for the piston-side valve case 16, also equipped with an exterior plug-in piece 19 comprising on its part several circumferential, parallel and equidistant ribs, which ribs can be snapped in and engage sealingly with the correlated plug-in receptacle 29 on the interior of the piston 1. There then, the piston-side valve case 16 and the correlated piston 1 are joined in an absolutely secure, non-slipping, and adhesive-free bond.

The valve flap disposed in the piston-side valve case 16 is designated as 17, while the valve flap disposed in the cylinder-side valve case 15 has the number 9.

Both valve cases 15, 16 are equipped with the bottom 18 mentioned above, each equipped with a through hole 33, as shown in FIGS. 7 and 8.

The valve flap 9, 17 is constructed from an easily bendable synthetic elastomeric material which, for example, is constructed as rubber strap or similar. According to FIGS. 7 and 8, the respective valve flap 9, 17 is equipped with an angular piece 21 transitioning at its free lower end into a rib 22 of greater width.

With the said angular piece 21 and the rib 22, the respective valve flap 9, 17 is inserted through a correlated slit 23 in the area of the bottom so that the rib 22 comes to rest as snap-in rib at the opposite side of the slit 23. In this process, the rib 22 enters the area of a release 34 of the piston-side valve case 16 (see FIG. 7).

In the same manner, the valve flap 9 also is connected to the cylinder-side valve case 15 and inserted into the slit 23 mentioned there, as well.

The upper edge of the slit 23 lies slightly higher than the surface of the bottom 18 so that the respective valve flap 9 comes to rest sealingly against the through-hole 33 under elastomeric spring force.

In FIG. 5, it can still be seen that the bore 5 disposed at the upper end in the area of the head 2 of the piston 1 is disposed in the area of a deepened bead 28. When pressing on the head 2 with the ball of the thumb, the bore 5 is not closed thereby, because the air flows laterally past the ball of the thumb through the bead 28 cupping the bore.

The seal between the internal circumference of the piston 1 and the external circumference of the cylinder 4 is achieved by disposing in the area of the external circumference of the cylinder 4, at least one radially inward-pointing sealing bulge 37 coming to rest sealingly against the external circumference 3 8 of the piston 1 and extending along the same.

The radially outward-pointing circular bulge 41 disposed at the lower free end of the plug-in piece 24 serves for additional sealing of the valve case 15 on the internal circumference of the cylinder mantel of the cylinder 4.

Here then, longitudinal grooves 40, disposed in even distribution on the circumference, engage with the correlated ridges 31 of the twist protection 27 in the internal circumference of the cylinder 4 in the area of the valve case 15 in a twist-protected snap-in connection.

In order to prevent the piston 1 from being driven through the cylinder 4, thereby causing damage, it is provided that the underside of the head 2 be equipped with a radially outward-pointing stop edge 35 operating in conjunction with a correlated stop edge 36 disposed at the upper end of the cylinder 4.

Herein, the total length of the piston 1 is less than the total length in the interior of the cylinder 4 so that it is always ensured that first, the stop edges 35 and 36 engage with one another before the piston-side valve case 16 enters into collision with the cylinder-side valve case 15.

Overall, the present invention achieves the advantage that a tool-less, adhesive-free assembly of an air extractor pump is provided and that the said pump works particularly reliably and simply and can be produced particularly cost-effectively.

Legend of the Drawings

-   1 piston -   2 head -   3 arrow direction 3′ -   4 cylinder -   5 bore -   6 arrow direction -   7 arrow direction -   8 arrow direction -   9 valve flap (cylinder) -   10 filler neck (waterbed) -   11 water -   12 screw neck -   13 closure cap -   14 screw-on cap -   15 valve case (cylinder) -   16 valve case (piston) -   17 valve flap 17 (piston) -   1 8 bottom -   19 plug-in piece (of 16) -   20 air extractor pump -   21 angular piece -   22 rib -   23 slit -   24 plug-in piece (of 15) -   25 circular collar -   26 circular groove -   27 twist protection -   28 bead -   29 plug-in receptacle (of 1) -   30 plug-in receptacle (of 4) -   31 ridge -   32 internal thread (of 15) -   33 through-hole -   34 release -   35 stop edge -   36 stop edge -   37 sealing bulge -   38 external circumference -   39 protuberance -   40 longitudinal groove (for ridge 31) -   41 circular bulge -   42 air 

1. An air extractor pump for waterbeds comprising a piston (1) held with longitudinal slideability in a cylinder (4), wherein the piston (1) and the cylinder (4) each are equipped at their back ends as seen in insertion direction (3′) with a valve flap (9, 17) closeably covering one through-bore (33) each, wherein the front end of the piston (1) as seen in insertion direction (3′) is equipped with a discharge bore (5), and wherein at the back end of the cylinder (4) as seen in insertion direction (3′), a thread (32) is provided wherewith it can be screwed onto a correlated screw neck (12) of a filler neck (10) of a waterbed, wherein the valve flaps (9, 17) are attached in the area of separately constructed valve cases (15, 16), and wherein the piston-side valve case (16) as well as the cylinder-side valve case (15) each are equipped with a plug-in piece (19, 24) engaging with the plug-in receptacles (29, 30) of the piston (1) or the cylinder (4), respectively, in a correlated, sealed snap-in connection.
 2. An air extractor pump according to claim 1, wherein the cylinder-side valve case (15) is equipped with a radially exterior plug-in piece (24) comprising several parallel, circumferential, circular bulges (41), said circular bulges (41) snapping sealingly into the correlated plug-in receptacle (30) on the interior of the cylinder (4).
 3. An air extractor pump according to claim 2, wherein the piston-side valve case (16) is equipped with a radially exterior plug-in piece (19) comprising several circumferential, parallel, and equidistant ribs, said ribs snapping sealingly into the correlated plug-in receptacle (29) on the interior of the piston (1).
 4. An air extractor pump according to claim 3, wherein the cylinder-side valve case (15) and/or the piston-side valve case (16) are held in the cylinder (4) and/or the piston (1), respectively, and protected from twisting by means of a twist protection (27, 40).
 5. An air extractor pump according to claim 4, wherein the twist protection (27, 40) between cylinder-side valve case (15) and cylinder (4) is achieved by constructing radially inward-pointing ridges (31) in the cylinder (4), said ridges (31) working in conjunction with correlated, longitudinally extending longitudinal grooves (40) on the external circumference of the valve case (15), thereby affixing the same and protecting it from twisting.
 6. An air extractor pump according to claim 1, wherein the respective valve flap (9, 17) is snapped into a correlated slit (23) in the bottom surface (18) of the respective valve case (15, 16) by means of ribs (22) in the manner of a snap-in connection.
 7. An air extractor pump according to claim 1, wherein the thread (32) to be screwed onto the screw neck (12) of the filler neck (10) of the waterbed is disposed as internal thread in the cylinder-side valve case (15).
 8. An air extractor pump according to claim 7, wherein the cylinder-side valve case (15) is equipped in the area of the internal thread (32) with a radially internal and axially outward-extended circular collar (25) radially supporting the screw neck (12) of the filler neck (10) while the said screw neck (12) is screwed on.
 9. An air extractor pump according to claim 6, wherein the valve cases (15, 16) are manufactured in an injection molding procedure. 